There were two Francis J. Lehmans'. One was "junior" and the other was a "senior." Francis J. Lehmans, Sr. was married to Susanah Abernathy and married December 18, 1824. Francis was born in 1790 and died in 1866 making him 76 years old. He is shown in the 1860 census living with the Loftin family. Mary Loftin was the daughter of Francis, senior and Susanah Abernathy (Lehmans). I have searched endlessly for Susanah Abernathy (wife of Francis, senior) to verify her parents.
On the other hand, Francis J. Lehmans, Junior, married Susan Goodson (sister of George W. Goodson also a few houses down on the 1860 census) on Sept 29, 1861. I believe that the Francis J. Lehmans you are refering to is this one. I know that Susan died very young so she and Francis, Jr. are likely the ones with kids that lived with the grandparents. If that is the case, their grandparents would be Aaron Goodson (1808-1877.)
My concerns are with Francis J. Lehmans, senior. I do not know if the Lehmans' were Jewish. I believe that they may have been. I have noticed that in the DNA make-up of several DNA tested relatives the presence of Eastern European Jewish DNA. That would explain the mysterious presence in what is ordinarily Scots Irish, English, German, and French blood.